A counter-terrorism boss in Jakarta has told the ABC that police chiefs were just preparing security forces for the worst possible outcome.

Bali's governor, I Made Pastika, says authorities have made strong preparations to prevent anything happening.

A 1,500-strong security force will provide security for the event.

Ms Gillard says she remains determined to go.

"I want to be in Bali - this is a moment of real significance for our nation," she told reporters this morning.

"I mean, 10 years years ago we would all remember where we were and how we felt, how shocked they were.

"I want to spend some time with the families who have really had to absorb such grief , but also for the nation, speak about the journey over the 10 years since, and everything that we've done to counter the threat of terrorism in Australia and beyond our shores.

"It's what took to us to Afghanistan and we're still there making sure Afghanistan doesn't become a safe haven again for the training of terrorists who take Australian lives."

Former prime minister John Howard will also head to Bali and says he is sure Indonesian authorities are doing everything they can to ensure people are safe.

"Those who want to go, many of them are already there, they will still go," he said.

"It's a very important thing emotionally to them."

Elite anti-terrorism units, the bomb squad and heavily armed police brigades were given their final instructions yesterday on combating any terror threats.